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Ls swap ..no spark

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Old 06-08-2020, 08:36 PM
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Car: 89 iroc 98 T/A
Engine: LSX
Transmission: T56
Ls swap ..no spark
Vats tuned out...my fuel pump primes 60psi .. injectors pulse I plugged up old injector and checked with test light to verify ..Coils have good 12v good ground and good low reference.. it’s like pcm does not send signal to fire coil. Could it be cam or crank sensor? How would you check? Can you view this through live data on a scan tool? Thanks for any help
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Old 06-08-2020, 11:39 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: Ls swap ..no spark
Are you sure VATS was properly turned off?
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Old 06-09-2020, 04:53 AM
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Car: 89 iroc 98 T/A
Engine: LSX
Transmission: T56
Re: Ls swap ..no spark
Originally Posted by five7kid
Are you sure VATS was properly turned off?
i am starting to wonder.. It was in another one of my irocs already ls1/cam t56 I put engine in another car with a 4l60e and had my tuner swap some stuff for it to run automatic..maybe something happened there
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Old 06-09-2020, 12:02 PM
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Re: Ls swap ..no spark
Vats or crank sensor will stop the engine from running. Check your crank sensor connector also
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Old 06-09-2020, 02:06 PM
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Car: 89 iroc 98 T/A
Engine: LSX
Transmission: T56
Re: Ls swap ..no spark
Originally Posted by 86iroc504
Vats or crank sensor will stop the engine from running. Check your crank sensor connector also
ill check that tonight.. I know I have 12 volts to the crank plug ..but I’ll ohm back to pcm plug .. my other car has Ls/t56 I may even swap computers but will it start my auto car? Maybe ground clutch signal pin b34?
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Old 06-09-2020, 05:57 PM
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Car: 89 iroc 98 T/A
Engine: LSX
Transmission: T56
Re: Ls swap ..no spark
So I checked cam and crank sensor both have good 12v and good low reference ground.. also checked both sensors while cranking car ..signal wire to low reference ground and I get varying voltages like it’s reading correctly (I’m assuming) On both cam and crank sensors .. pointing me to pcm I believe, maybe vats or something crazy changed when tuner put in stuff for 4l60
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Old 06-09-2020, 06:15 PM
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Car: 86 Camaro
Engine: '03 4.8 vortec
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Axle/Gears: 3.42
Re: Ls swap ..no spark
Originally Posted by 91z28 98ta
So I checked cam and crank sensor both have good 12v and good low reference ground.. also checked both sensors while cranking car ..signal wire to low reference ground and I get varying voltages like it’s reading correctly (I’m assuming) On both cam and crank sensors .. pointing me to pcm I believe, maybe vats or something crazy changed when tuner put in stuff for 4l60
Check to see if you have 12volts at coils, injectors,etc when engine is cranking. Those key hot wires have to be tied to ignition hot( hot while engine is cranking)
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Old 06-09-2020, 07:49 PM
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Car: 89 iroc 98 T/A
Engine: LSX
Transmission: T56
Re: Ls swap ..no spark
Originally Posted by 86iroc504
Check to see if you have 12volts at coils, injectors,etc when engine is cranking. Those key hot wires have to be tied to ignition hot( hot while engine is cranking)
I have checked that as well.. I have voltage while engine is cranking.. voltage does drop but I’m thinking that’s because the amp draw of starter
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Old 06-09-2020, 09:29 PM
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Re: Ls swap ..no spark
Originally Posted by 91z28 98ta
I have checked that as well.. I have voltage while engine is cranking.. voltage does drop but I’m thinking that’s because the amp draw of starter
If your fuel pressure is good, what about your grounds
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Old 06-12-2020, 05:21 AM
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Re: Ls swap ..no spark
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Last edited by 91z28 98ta; 06-12-2020 at 05:27 AM. Reason: Double post
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Old 06-12-2020, 05:25 AM
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Car: 89 iroc 98 T/A
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Re: Ls swap ..no spark
Update.. crank position sensor was bad, which was brand new out of the box go figure.. thanks again for the help
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Old 06-12-2020, 09:17 AM
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Re: Ls swap ..no spark
Originally Posted by 91z28 98ta
Update.. crank position sensor was bad, which was brand new out of the box go figure.. thanks again for the help
What brand is that
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Old 06-13-2020, 05:41 AM
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Car: 89 iroc 98 T/A
Engine: LSX
Transmission: T56
Re: Ls swap ..no spark
Originally Posted by 86iroc504
What brand is that
BWD
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